After three weeks of tech earnings reports, we have seen such major companies as Apple Inc. and Amazon.com Inc. hammered after poor forecasts, but the real danger for tech is being voiced by companies that are not such household names.

Several semiconductor companies are seeing a slowdown, and, even though they may be in the minority for now, they should not be ignored. Semiconductors, because of where they sit in the global supply chain and how pervasive their use is across so many products, can sound alarms about tech-ecosystem weakness that could be right around the corner.

“This is really a difficult and sensitive point, where we are trying to figure out if it is kind of modest or a lot more serious,” said Christopher Rolland, an analyst at Susquehanna Financial Group. “It’s really hard to tell because we are seeing [that] some guys are feeling it worse than others. The truth is that the real slowdown won’t be here until [the first quarter of 2019], if indeed this is going to be a pronounced slowdown.”

Three areas were cited in several earnings reports and conference calls from chip makers and related companies: the automotive, industrial (chips for manufacturing floors and automation) and consumer segments. Some analysts believe the chip industry, which has been on a huge roll both in terms of demand and in stock-price gains, is due for another downturn, despite executives’ statements that their industry is no longer cyclical in nature. The warning signs are all there.

The generally conservative tone on product demand from TI was echoed by another large hardware company, storage company Western Digital Corp.
WDC, -3.20%
, and a few smaller chip makers, such as Lattice Semiconductor Corp.
LSCC, -4.83%LSCC, -4.83%
and Cypress Semiconductor Corp.
CY, -3.64%
Lattice said it was seeing slowness in the industrial and consumer markets, particularly in Asia, due to “conservatism related to the macroeconomic conditions and tariffs,” while Cypress said it was seeing “softness across the board,” but the downside was in the consumer and industrial segments. Lattice said its fourth quarter outlook also reflected “an expected inventory reduction at some distributors” which it expects to be partially offset by strength in the communications and computing markets.

Western Digital’s disappointing first fiscal quarter report fueled an 18% drop in its shares after its report last week, and Chief Executive Stephen Milligan told analysts that the “current geopolitical and industry dynamics are creating a more challenging global business environment.” And, as some analysts have been predicting since the start of the Trump administration’s trade conflict with China, trade dynamics “are causing our customers to be more conservative, resulting in a demand slowdown for our products,” he said.

While TI is pointing to a broader slowdown in a range of its semiconductors, used in devices ranging from automobiles to industrial machines, Western Digital’s woes appear to be mostly related to an overabundance of flash memory, and said it would idle some of its manufacturing capacity to reduce inventories. Following semis, storage is another component which could also portend growth issues in servers or data centers.

NXP Semiconductors NV
NXPI, -4.25%
reported a better-than-expected third quarter this week, helping fuel a 14% jump in its shares at one point, but it was slightly cautious about the fourth quarter, giving a wider-than-normal revenue range in its outlook. NXP, like TI, is a big player in the automotive market. But, in general, it was far more upbeat than some of its chip brethren.

“We realize there’s a significant amount of investor angst about the next couple of quarters in the semiconductor market,” NXP Chief Executive Richard Clemmer told analysts in the company’s post-earnings-report conference call. “What we have seen in the automotive market is a modest slowdown primarily due to the WLTP testing [a global emissions standard] bottlenecks in Europe and lower car sales in China.”

He added that there is no apparent excess NXP inventory in its customer supply chain. “To be clear, we have not experienced any weakness in the typical leading indicators, including unusual backlog cancellations or any program cancellations.”

Jonathan Golub, chief equity strategist at Credit Suisse, noted in a report that the rest of the technology sector so far has remained a standout in earnings growth, with strength in cloud computing and software as a service.

“Surprises have been broad-based, with over 90% of names beating EPS expectations,” Golub said. “Outside of semis, price action has been largely positive.”

The semiconductor business has been growing steadily since the last downturn in 2015, and it’s feasible that the current slowing in growth among some companies could portend an industrywide downturn. Sales in 2017 represented the best year yet, with global sales of $412.2 billion, a jump of 21.6% from 2016.

Stacy Rasgon, a Bernstein Research analyst, wrote about the disparity between Intel and the rest of the semi bunch in a note Friday. Rasgon wrote that, while there was nothing to quibble about in Intel’s excellent earnings, “We now appear to be ‘officially’ moving into a semiconductor downturn; to that end the question of sustainability is likely to become the primary tactical controversy on Intel over the next several quarters.

Bernstein’s Rasgon made a comment in his note on Intel that could be applied more broadly to others in tech. “So far Intel is apparently not seeing any issues, but this sort of thing has a tendency to sneak up on you; it remains something to watch.”

Those words could apply to the rest of the tech sector, possibly as soon as early next year. Rolland of Susquehanna expects that, by the January reporting cycle, it will be more clear if there is a real downturn. Investors who are concerned that the news won’t be good when we get there might want to consider looking to a different sector for safety.

Get the top tech stories of the day delivered to your inbox. Subscribe to MarketWatch's free Tech Daily newsletter. Sign up here.

Intraday Data provided by SIX Financial Information and subject to terms of use. Historical and current end-of-day data provided by SIX Financial Information. All quotes are in local exchange time. Real-time last sale data for U.S. stock quotes reflect trades reported through Nasdaq only. Intraday data delayed at least 15 minutes or per exchange requirements.